30 IREC Farmers' Newsletter No. 199 — Autumn 2018 Viewing operations at Cubbie Station Cubbie Ag comprises three properties located near Dirranbandi and St.George in southern Queensland, with 22,000 ha developed for irrigation from a total area of 93,000 ha. Cubbie Station at Dirranbandi was purchased by Des Stevenson in 1983, who in his retirement began development of previously grazed land for irrigation. The irrigation layout is split by the floodplain and as it is unlawful to impede the flow of water over the floodplain, any irrigation infrastructure that crosses the floodplain must be below ground level. Cubbie Station’s total water storage capacity of 462,000 ML is sourced from the Culgoa and Balonne Minor rivers on the Lower Balonne river system, as well as a floodplain water component in medium to large flood events. Water taken for irrigation, both diversion from the rivers and floodplain harvesting, is according to water license entitlements, with water take metered and reported daily. All water harvesting is determined by the announced flow over Jack Taylor Weir at St. George, which is administered by the Queensland Department of Natural Resources, Mines and Energy (DNRM). The majority of water extracted by Cubbie Ag is diverted from the rivers by gravity rather than pumped. The layout of the property down the floodplain allows for gravity irrigation but in full production years, two thirds of the area requires irrigation water to be pumped to fields. The Cubbie floodplain licences were determined by calculating the volume of water which would have naturally been consumed through seepage, evaporation and evapotranspiration in the field and storage areas, which are now levied off from the floodplain. The Water Resources Plan states extracting this volume of water has no impact on the volume of water passing downstream of Cubbie. Cubbie water storages cover 11,000 ha and only fill fully in major flood events, which occur on average, one year in ten. Smaller flood events allow partial filling — always under licence conditions. If storages are full there is enough water for two years of full production, assuming average in-crop rainfall. This season, due to lack of water, there are only 1800 ha of cotton being grown, on one metre rows. This is less than 10% of Cubbie’s cotton capacity, with the long-term average being 12,000 ha per year. Opportunity to spark new ideas Thanks to Riverina Local Land Services and CRDC for making this tour so affordable. It was a tremendous experience for all, with everyone saying it is beneficial to visit farms in other irrigation regions. Most people said they would adopt something in their business as a result of the tour. These included using storages to give more control and faster irrigations, greater investigation into the best paddocks for future re- development taking into consideration slope and crops and use of soil moisture monitors. Further information Iva Quarisa T: 02 6963 0936 E: [email protected] W: www.irec.org.au Southern irrigators inspecting some of the 1800 ha of cotton growing at Cubbie station this season, while on the Maximising Irrigation Profitability tour.